THE LIMBS OF LIZARDS 133 



It is to be particularly noted that according to this 

 view the cause of the variation in the lizard is some- 

 thing extraneous to itself — its environment, in the 

 first place, — and that the variation having once 

 occurred, is transmitted by the influence of what is 

 called heredity. 



On the other hand, according to the Darwinian 

 view, the initial factor in the variation of the four- 

 limbed lizard is not to be sought for in extraneous 

 circumstances such as environment, but in the inherent 

 nature of animal life. All admit that the variations 

 take place, but the newer theory is that these varia- 

 tions arise spontaneously. That does not mean that 

 they arose in a haphazard way necessarily, but that 

 they are the result of the operation of a law con- 

 cerning which we know nothing. It means that it 

 is the property of germ plasm to vary, whether the 

 environment changes or not. The result of these 

 variations may be useful to the creature or otherwise. 

 In this case, if one of these spontaneous variations in 

 the lizard took the shape of a reduction in the size of 

 the limbs at a time when limbs were rather in the 

 way than otherwise, then that variation would confer 

 an advantage upon those individuals in which it 

 occurred. If their life depended upon being able to 

 burrow or otherwise protect themselves in some special 

 way which limbs interfered with, it is obvious that 

 the members of the race which had this new character 

 would be the survivors in the struggle for life. If 



